Submitted to: Immunogenetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/31/2005
Publication Date: 8/6/2005
Citation: Rodriguez, M.F., Wiens, G.D., Purcell, M., Palti, Y. 2005. Characterization of toll-like receptor 3 gene in rainbow trout (oncorhynchus mykiss). Immunogenetics 57(7):510-519. Online pub date 2005 Aug 6, :1-10.
Interpretive Summary: The U.S. salmonid aquaculture industry suffers severe economic loss to diseases. In recent years, viral epidemics and bacterial infections in farmed Atlantic salmon and rainbow trout have resulted in production losses of greater than 90% accounting for millions of dollars of lost revenue. As part of the effort to identify genes that affect aquaculture production traits (CRIS 106-1930-31000-006-00D) scientists at the NCCCWA identify candidate genes for further genomic and functional characterizations. Those genes are selected based on their sequence homologies to functionally annotated genes from better studied species. Toll-like receptors (TLRs) are responsible for pathogen identification and subsequent host immune response activation. Several TLRs have been described in a variety of species, each one recognizing different pathogen structures. This report is part of our long term effort to characterize and map TLRs in rainbow trout. Here we report the identification and characterization of the rainbow trout TLR3, which is thought to be important for virus identification by the immune system.
Technical Abstract: Toll-like receptors (TLRs) are responsible for pathogen identification and subsequent host immune response activation. Several TLRs have been described in a variety of species, each one recognizing different pathogen structures. We identified a rainbow trout EST that showed high sequence homology to TLR3 genes in other species. The TLR3 signaling pathway in mammals is activated upon presence of viral components (double stranded RNA) with stimulation of nuclear factor kappa B and type I interferon expression. The 4613bp cDNA sequence of the putative TLR3 was translated in silico to a 913 amino acid peptide with distinct TLR motifs, such as leucine-rich repeats (LRR) and Toll/IL-1R (TIR) domains. The rainbow trout (Oncorhynchus mykiss) TLR3 (omTLR3) was found to be expressed in a wide range of tissues using reverse transcriptase (RT) PCR. Further functional analysis suggested that the rtTLR3 signaling pathway is likely to be similar to the mammalian pathway